US3006965A

US3006965A - Thiomethylals and preparation thereof

Info

Publication number: US3006965A
Application number: US714696A
Authority: US
Inventors: Schrader Gerhard
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1957-03-01
Filing date: 1958-02-12
Publication date: 1961-10-31
Anticipated expiration: 1978-10-31

Description

United States Patent r 3,006,965 THIOMETHYLALS AND PREPARATION THEREOF Gerhard Schrader, Wuppertal-Cronenberg, Germany, as-

signor to Farbenfabriken Bayer Aktiengesellschaft,

Leverkusen, Germany, a corporation of Germany No Drawing. Filed Feb. 12, 1958, Ser. No. 714,696 Claims priority, application Germany Mar. 1, 1957 5 Claims. (Cl. 260-609) The present invention relates to and has as its objects new and useful thiomethylals of the following general formula wherein R stands for a cycloalkyl radical or for an alkyl radical having l-lZ carbon atoms which may be substituted, or for the cyano radical, are excellent insecticides. More specifically R stands for cyclo alkyl radicals containing 5 to 6 carbon atoms. The alkyl radical if substituted, preferably bears 1 or 2 substituents of mercaptans. v

This reaction may be seen from the following formula In this formula R has {the same significance as shown above.

. The preparations obtainable according to this process are chiefly water-insoluble oils, some of which may be distilled without decomposition under a high vacuum. Partly, solid compounds are obtained which may be recrystallized from suitable organic solvents.

The new compounds are distinguished by an insecticidal activity. It is a characteristic feature of most of the compounds of this class to have a distinct acaricidal action. The compounds according to the invention are employed in a manner commonly used for plant-protecting agents, i.e. they are preferably used in combination with liquid or solid diluents or fillers. Fillers and diluents of this kind are for example talcum, chalk, benton- "ite, and alumina, on the one hand, or, in the case of liquid agents, preferably Water (if desired in combination with a commercial emulsifier, such as preferably aromatic polyglycolethers eg. a commercially available benzylhydroxy diphenyl polyglycolether containing about gly-.

. col residues) as well as low molecular weight alcohols,

Killing rate has been determined after 24 hours.

hydrocarbons and the like. A preferred method of application consists in using a dusting or spraying process. As an example for the special utility of the inventive compounds the compounds of the following formulae 01- S CHz-S C N Cl S-CHr-SCmHrs (III) CH3 01 S C Hr- S -CH have been tested against spider mites (tetranychus althaeae Hanst) and caterpillars (larvae of diamond black moth). Tests have been carried out as follows: plants (nasturtium plants in case of spider mites and white cabbage in case of caterpillars) have been sprayed drip wet. The following results have been obtained:

(1) Spider mites, 0.1%, 100% (II) 'Spider mites, 0.1%, 100% 2 (III) Caterpillars, 0.1%, 100%.

The solutions of the active ingredients have been prepared as follows: equal amounts of active ingredient and dimethyl formamide have been mixed, whereafter 20% by weight referred to active ingredient of a commercially available emulsifier (such as benzylhydroxy diphenyl polyglycolether containing about 15 glycol residues) are added. This premixture then is diluted with water to a concentration of 0.1%.

The following examples are given by way of illustration only without, however, limiting the present invention thereto:

Example 1 21 grams of sodium thiocyanate are dissolved in millilitres of methanol. 59 grams of u-chloromethyl-(4- chlorophenyl)-thioether are added at 50 C. with stirring Whilst maintaining the temperature at 50 C. for 2 hours. The mixture is then cooled to room temperature, the sodium chloride formed is filtered off by suction and the solvent removed by vacuum distillation. After standing for a brief period, the residue solidifies. Upon recrystallisation frorn ligroin, 45 grams of a-methyl thiocyanate-(4-chlorophenyl) thiomethylal of MP. 69 C. is obtained.

Administered to the rat per os 1000 mg./kg. do not show any symptoms. 0.0001 percent solutions kill mosquito larvae 0.1 percent solutions kill red spider mites and black bean aphids completely.

Example 2 oil is taken up in benzene, the benzenic solution is 3 washed with water and dried over sodium sulfate. After removal of the solvent by vacuum distillation 83 grams of p-chlorophenyl-dodecylthiomethylal of B.P. 167 -C./0.01 mm. Hg are thus obtained.

Administered orally to the rat, 1000 mg./kg. do not show' any symptoms. 0. 1 percent solutions kill mosquito larvae, aphids and spider mites completely. Caterpillars are also killed completely with. 0.1 percent solutions.

Example 3 37 grams of 3.4-dichlorophenyl mercaptan are dissolved in 63 grams of a sodium eth-ylate solution (cone-- Example 4 Cl-Q-S-CHaS-CH 31 grams of a-chloromethyl-isopropyl-thioether (B.P. 145 C./ 15 mm. Hg) are added dropwise with stirring to a mixture of 39 grams of p-chlorophenyl mercaptan and 78 grams of a sodium ethylate solution (corresponding to A of sodium ethylate) and 100 millilitres of anhydrous alcohol. The temperature rises spontaneously to 60 C. and is maintained for one hour. After working up in usual manner 49 grams (corresponding to 85 percent of the theoretical) of p-chlorophenyl-isopropyl-thiomethylal of B.P. 95 C./0.01 mm. Hg are thus obtained.

Toxicity on the rat orally: LD 1000 mg/kg. 0.1 percent solutions kill caterpillans 100%. In a similar manner the following compounds may be obtained:

CH1 Cl S-CHr-S-CH Cam B.P. 115 C./0.01 mm. Hg;

CaHa

B.P. 100 C./0.01 mm. Hg;

ClQ-S-CHz-S-OlEh-OHr-Cl cockroaches are killed completely with solution of 0.1 percent; B.P. 110 C./0.01 mm. Hg;

0.1 percent solutions kill black bean aphids 50%; B.P.

with 0.1% solutions black bean aphids are killed 60%;

with 0.1 percent solution-s spider mites are killed 50%;

MP. 62 C.;

black bean aphids are killed completely with solutions of 0.1%, 0.1% solutions show a strong ovicidal activity against the eggs of red spiders; B.P. C./0.01 mm.

GIG-S-CHPSGMHK with solution of 0.1% caterpillars are killed 50%; B.P. C./0.0I mm. Hg.

I claim:

1. The compound of the following formula 2. The. compound of the following formula 3. The compound of the following formula 4. The compound of the following formula 5. A thiomethylal of the general formula X I R-S-CHz-SQ-Ol wherein R stands for a member selected from the group consisting of cycloalkyl radicals containing 5 to 6 carbon atoms, chloro-substituted lower alkyl radicals and chlorosubstituted phenylmercaptomethyl radicals; and X stands for a member selected from the group consisting of hydrogen and chlorine.

References Cited in the file of this patent UNITED STATES PATENTS 2,490,875 Landau Dec. 13, 1949 2,617,818 Mowry Nov. 11, 1952 2,645,592 Campbell July 14, 1953 2,665,202 Mowry Jan. 5, 1954 2,743,210 Jones Apr. 24, 1956 2,788,355 Bullock Apr. 9, 1957 2,789,990 Bullock Apr. 23, 1957 2,797,246 Barber June 25, 1957 2,801,261 Hornberger July 30, 1957 2,802,769 Van Stryk Aug. 13, 1957

Claims

5. A THIOMETHYLAL OF THE GENERAL FORMULA